1. Field of the Invention
This invention relates to a lawn mower for directing grass clippings to a grass catcher. More particularly the invention relates to a lawn mower including a mower unit supported to be vertically movable by a vehicle body and having a receiving plate with a receiving surface for covering a downward opening of a glass clippings discharge channel connected to a housing of the mower unit for rearwardly directing the grass clippings cut by cutting blades, in which the receiving plate is swingable about a transverse shaft between a grass clippings guiding position where the receiving surface extends parallel to a flow of grass clippings through the grass clippings discharge channel and a grass clippings removing position where the receiving surface has a large tilt angle relative to the ground.
2. Description of the Related Art
One example of the above-noted conventional lawn mower is disclosed in Japanese Patent Publication Kokai No. 2001-45827. In the conventional mower, the receiving plate provided in the downward opening of the grass clippings discharge channel is vertically swingable about the transverse support shaft in response to operation of a control lever attached to the housing, thereby to easily remove the grass clippings adhering to the receiving surface of the receiving plate.
With such a structure, the greater the fore and aft length of the receiving plate is, the higher grass collecting performance is expected. However, when the receiving plate having an increased fore and aft length is vertically swung, there is a possibility of the receiving plate being deformed through contact at a distal end portion thereof with the ground. Such deformation of the receiving plate lowers the grass clippings guiding performance, which results in an unsmooth transportation of the grass clippings to the grass catcher.
An object of this invention is to provide a lawn mower having an improved structure for easily removing grass clippings adhering to a receiving plate through vertical pivotal movement of the receiving plate, and yet preventing deformation of the receiving plate through contact with the ground even where the receiving plate has a long rearward extension to improve the grass collecting performance.
The above-noted object is fulfilled, according to this invention, by a lawn mower for directing grass clippings to a grass catcher, the lawn mower comprising a vehicle body, a mower unit supported by the vehicle body to be vertically movable for varying a height thereof above the ground, the mower unit including a housing, cutting blades rotatable about vertical shafts, and a grass clippings discharge channel connected to the housing and opening downward for rearwardly directing grass clippings cut by the cutting blades, a receiving plate having a receiving surface for covering the downward opening of the grass clippings discharge channel, the receiving plate being pivotable about a transverse shaft between a grass clippings guiding position in which the receiving surface extends parallel to a flow of grass clippings through the grass clippings discharge channel and a grass clippings removing position in which the receiving surface has a large tilt angle relative to the ground, a control mechanism for swinging the receiving plate, and a swing range limiting mechanism for reducing a swing range of the receiving plate as the mower unit is lowered relative to the ground.
With this construction, when the mower unit is raised high above the ground, the receiving plate is vertically swung within a relatively large range that is limited by taking into account the rearward extension of the receiving plate and the height of mower unit of that time. On the other hand, when the mower unit is lowered close to the ground, the receiving plate is vertically swung within a relatively small range that is limited by taking into account the rearward extension of the receiving plate and the height of mower unit of that time. Thus, while the receiving plate is given the increased fore and aft length to improve the grass collecting performance, the receiving plate is vertically swung to remove easily the grass clippings adhering to the receiving plate. Since the limiting mechanism appropriately limits the swinging range of the bottom wall, the receiving plate is vertically swingable within a limited range in which the receiving plate does not contact the ground regardless of the height of the mower unit over the ground.
In order to simplify the swing range limiting mechanism, it is desirable to incorporate the limiting mechanism into the control mechanism. In a specific example of such a swing range limiting mechanism, the control mechanism includes a control rod linked to the receiving plate, and the swing range limiting mechanism has a contactable member provided in the vehicle body and a contact member provided in the control rod to be placed closer to the contactable member as the mower unit is lowered relative to the ground.
With the limiting mechanism including the contactable member and the contact member, it is dear that this lawn mower has a simplified structure, and thus low manufacturing cost, as compared with a structure employing a stop mechanism having a sensor for detecting a height of the mower unit above the ground and an electromagnetic cylinder for varying the swingable range of the receiving plate from the grass clippings guiding position based on results of detection by the sensor.
With the swing range limiting mechanism according to this invention being employed, it is not required to visually confirm a positional relationship between the receiving plate in vertical pivotal movement and the ground, which makes it possible to provide the control mechanism for the receiving plate to be operable by the driver seated on the driver""seat.